Flame-resistant polycarbonate blends

ABSTRACT

The present invention provides thermoplastic polycarbonate blends which contain phosphonate amines and special graft polymers, which are prepared using redox initiator systems, and which are characterised by improved mechanical properties such as notched impact resistance, weld line strength and stress crack resistance.

The present invention provides thermoplastic polycarbonate blends whichcontain phosphonate amines and special graft polymers, which areprepared using redox initiator systems, and which are characterised byvery good mechanical properties.

U.S. Pat. No. 4,073,767 and U.S. Pat. No. 5,844,028 describe cyclicphosphorus compounds including phosphorinane rings as suitable flameretardants for polyurethanes, polycarbonates, polyesters and polyamides.In U.S. Pat. No. 4,397,750, specific cyclic phosphonate esters aredescribed as efficient flame retardants for polypropylene and otherpolyolefins. U.S. Pat. No. 5,276,066 and U.S. Pat. No. 5,844,028describe specific (1,3,2-dioxaphospborinanemethane) amines which aresuitable flame retardants for polyurethanes, polyesters, styrenepolymers, PVC, PVAc or polycarbonate.

U.S. Pat. No. 3,505,431, FR-P 1 371 139, U.S. Pat. No. 3,711,577, U.S.Pat. No. 4,054,544 describe acyclic triphosphonate amines, some of whichare halogenated.

EP-A 0 640 655 describes moulding compositions made from aromaticpolycarbonate, styrene-containing copolymers and graft polymers whichcan be made flame resistant with monomeric and/or oligomeric phosphoruscompounds.

EP-A 0 363 608 describes flame resistant polymer mixtures made fromaromatic polycarbonate, styrene-containing copolymers or graftcopolymers and also oligomeric phosphates as a flame resistant additive.For many applications such as, for example, in the internal sections ofhousings, the heat resistance of these mixtures is often inadequate

U.S. Pat. No. 5,061,745 describes polymer mixtures made from aromaticpolycarbonate, ABS graft polymers and/or styrene-containing copolymersand with monophosphates as flame retardant additives. For the productionof thin-walled housing parts, the level of stress cracking resistance ofthese mixtures is often inadequate.

The object of the present invention is therefore the preparation ofPC/ABS moulding compositions which are characterised by a combination ofgood impact resistance, weld line strength and stress crackingresistance and also have a high heat resistance. This range ofproperties is demanded in particular for applications in the dataprocessing sector such as, for example, for thin-walled housings formonitors, printers, etc.

Surprisingly, it has now been found that, by using phosphonate aminesaccording to the invention and graft polymers which are prepared bymeans of a redox initiator system, flame resistant polycarbonate blendsare obtained which provide moulded articles with a combination of goodimpact resistance, weld line strength and stress crack resistance andalso have a high heat resistance.

The invention therefore provides blends containing

-   A) 40 to 99, preferably 60 to 98.5 parts by wt. of an aromatic    polycarbonate and/or polyestercarbonate-   B) 0.5 to 60, preferably 1 to 40, in particular 2 to 25 parts by wt.    of a graft polymer, characterised in that the graft polymers B    consist of-   B.1) 5 to 95, preferably 30 to 80 wt. % of one or more vinyl    monomers and-   B.2) 95 to 5, preferably 20 to 70 wt. % of one or more particulate    diene rubbers with a glass transition temperature of <10° C.,    preferably <0° C., in particular <−20° C., which are prepared by    emulsion polymerisation, wherein an initiator system consisting of    an organic hydroperoxide and ascorbic acid is used,-   C) 0 to 45, preferably 0 to 30, in particular 2 to 25 parts by wt.    of at least one thermoplastic polymer, selected from the group    consisting of thermoplastic vinyl (co)polymers and polyalkylene    terephthalates,-   D) 0.1 to 30 parts by wt., preferably 1 to 25 parts by wt., in    particular 2 to 20 parts by wt. of phosphonate amine of the formula    (I)    A_(3-y)-N—B_(y)  (I),    -   in which    -   A represents a group of the formula (IIa)    -   or (IIb)    -   R¹ and R², independently, represent an unsubstituted or        substituted C₁-C₁₀ alkyl group or an unsubstituted or        substituted C₆-C₁₀ aryl group,    -   R³ and R⁴, independently, represent an unsubstituted or        substituted C₁-C₁₀ alkyl group or an unsubstituted or        substituted C₆-C₁₀ aryl group or    -   R³ and R⁴ together represent an unsubstituted or substituted        C₃-C₁₀ alkylene group,    -   y has the numerical value 0, 1 or 2 and    -   B independently, represents hydrogen, an optionally halogenated        C₂-C₈, alkyl group, or an unsubstituted or substituted C₆-C₁₀        aryl group.-   E) 0 to 5 parts by wt., preferably 0.1 to 3 parts by wt., in    particular 0.1 to 1, quite specifically 0.1 to 0.5 parts by wt. of a    fluorinated polyolefin.    Component A

Aromatic polycarbonates and/or aromatic polyestercarbonates suitable foruse according to the invention in accordance with component A are knownfrom the literature or can be prepared by methods known from theliterature (to prepare aromatic polycarbonates see, for example,Schnell, “Chemistry and Physics of Polycarbonates”, IntersciencePublishers, 1964 and DE-AS 1 495 626, DE-OS 2 232 877, DE-OS 2 703 376,DE-OS 2 714 544, DE-OS 3 000 610, DE-OS 3 832 396; to prepare aromaticpolyestercaribonates see, for example, DE-OS 3 077 934).

Polycarbonates are prepared, for example, by reacting diphenols withcarbonic acid halides, preferably phosgene and/or with aromaticdicarboxylic acid dihalides, preferably benzenedicarboxylic aciddihalides, by the phase interface method, optionally using chainstoppers, for example monophenols, and optionally using trifinctional ormore than trifunctional branching agents, for example triphenols ortetraphenols.

Diphenols for preparing aromatic polycarbonates and/or aromaticpolyestercarbonates are preferably those of the formula (II)

wherein

-   A represents a single bond, a C₁-C₅ alkylene, C₂-C₅ alkylidene,    C₅-C₆ cycloalkylidene, —O—, —SO —, —CO —, —S —, —SO₂, or C₆-C₁₂    arylene group, to which further aromatic rings, optionally    containing heteroatoms, may be condensed,    -   or a group of the formula (III) or (IV)-   B each represent a C₁-C₁₂ alkyl group, preferably methyl or a    halogen, preferably chlorine and/or bromine,-   x each represent, independently, 0, 1 or 2,-   p is 1 or 0 and-   R⁵ and R⁶ can be selected independently for each X¹ and represent,    independently, hydrogen or a C₁-C₆ alkyl group, preferably hydrogen,    methlyl or ethyl,-   X¹ represents carbon and-   m is an integer from 4 to 7, preferably 4 or 5, with the proviso    that R⁵ and R⁶ are simultaneously alkyl groups on at least one X¹    atom.

Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols,bis-(hydroxyphenyl)-C₁-C₅-alkanes,bis-(hydroxyphenyl)-C₅-C₆-cycloalkanes, bis-(hydroxyphenyl)-ethers,bis-hydroxyphenyl)-sulfoxides, bis-(hydroxyphenyl)-ketones,bis-(hydroxyphenyl)-sulfones andα,α-bis-(hydroxyphenyl)-diisopropyl-benzenes and their ring-brominatedand/or ring-chlorinated derivatives.

Particularly preferred diphenols are 4,4′-dihydroxydiphenyl,bisphenol-A, 2,4-bis-(4-hydroxyphenyl)-2-methylbutane,1,1-bis-(4-hydroxyphenyl)-cyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl sulfone and theirdi- and tetrabrominated or chlorinated derivatives such as, for example,2,2-bis-(3-chloro-4-hydroxyphenyl)-propane,2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane or2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane.

2,2-bis-(4-hydroxyphenyl)-propane (bisphenol-A) is particularlypreferred.

The diphenols may be used individually or as any mixture thereof.

The diphenols are known from the literature or are obtainable by methodsknown from the literature.

Chain stoppers which are suitable for preparing thermoplastic, aromaticpolycarbonates are, for example, phenol, p-chlorophenol,p-tert.-butylphenol or 2,4,6-tribromophenol, but also long-chainalkylphenols such as 4-(1,3-tetramethylbutyl)-phenol in accordance withDE-OS 2 842 005 or monoalkylphenols or dialkylphenols with a total of 8to 20 carbon atoms in the alkyl substituents, such as3,5di-tert.-butylphenol, p-iso-octylphenol, p-tert.-octylphenol,p-dodecylphenol and 2-(3,5-dimethylheptyl)-phenol and4-(3,5-dimethylheptyl)-phenol. The amount of chain stoppers to be usedis in general between 0.5 mol. % and 10 mol. %, with respect to themolar sum of each of the diphenols used.

The thermoplastic, aromatic polycarbonates have mean weight-averagemolecular weights (M_(W), measured, for example, by ultracentrifuge orlight scattering measurements) of 10 000 to 200 000, preferably 20 000to 80 000.

The thermoplastic, aromatic polycarbonates may be branched in a knownmanner, in fact preferably by incorporating 0.05 to 2.0 mol. %, withrespect to the sum of the diphenols used, of trifunctional or more thantrifunctional compounds, for example those with three or more phenolicgroups.

Both homopolycarbonates and also copolycarbonates are suitable. Toprepare copolycarbonates in accordance with component A according to theinvention, 1 to 25 wt. %, preferably 2.5 to 25 wt. % (with respect tothe total amount of diphenols used) of polydiorganosiloxanes withhydroxy-aryloxy terminal groups may also be used. These are known (see,for example, U.S. Pat. No. 3,419,634) or can be prepared by methodsknown from the literature. The preparation ofpolydiorganosiloxane-containing copolycarbonates is described, forexample, in DE-OS 3 334 782.

Preferred polycarbonates, in addition to bisphenol-A homopolycarbonates,are the copolycarbonates of bisphenol-A with up to 15 mol. %, withrespect to the molar sum of diphenols, other than the diphenolsmentioned as preferred or particularly preferred, in particular2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane.

Aromatic dicarboxylic acid dihalides for preparing aromaticpolyestercarbonates are preferably the diacid dichlorides of isophthalicacid, terephthalic acid, diphenylether-4,4′-dicarboxylic acid andnaphthalene-2,6-dicarboxylic acid.

Mixtures of the diacid dichlorides of isophthalic acid and terephthalicacid in a ratio between 1:20 and 20:1 are particularly preferred.

When preparing polyestercarbonates, a carbonic acid halide, preferablyphosgene, is also used as a bifunctional acid derivative.

Suitable chain stoppers for use when preparing aromaticpolyestercarbonates are, in addition to the monophenols mentioned above,their chlorocarbonates and also the acid chlorides of aromaticmonocarboxylic acids, which may optionally be substituted by C₁-C₁₂alkyl groups or by halogen atoms, and also C₂-C₂₂ monocarboxylic acidchlorides.

The amount of each chain stopper is 0.1 to 10 mol. %, with respect, inthe case of phenolic chain stoppers, to the moles of diphenols and, inthe case of monocarboxylic acid chloride chain stoppers, to moles ofdicarboxylic acid dichlorides.

The aromatic polyestercarbonates may also contain copolymerised aromatichydroxycarboxylic acids.

The aromatic polyestercarbonates may be either linear or branched in aknown manner (with reference to this point, see also DE-OS 2 940 024 andDE-OS 3 007 934).

Branching agents which may be used are, for example trifunctional ormore than trifinctional carboxylic acid chlorides such as trimesic acidtrichloride, cyanuric acid trichloride,3,3′,4,4′-benzophenone-tetracarboxylic acid tetrachloride,1,4,5,8-naphthalenetetracarboxylic acid tetrachloride or pyromelliticacid tetrachloride, in amounts of 0.01 to 1.0 mol. % (with respect tothe dicarboxylic acid dichlorides used) or trifunctional or more thantrifunctional phenols such as phloroglucinol,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-hept-2-ene,4,4-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane,1,3,5-tri-4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)-ethane,tri-(4-hydroxyphenyl)-phenylmethane,2,2-bis-[4,4-bis-(4-hydroxyphenyl)-cyclohexyl]-propane,2,4-bis-(4-hydroxyphenylisopropyl)-phenol,tetra-(4-hydroxyphenyl)-methane,2,6-bis-(2-hydroxy-5-methylbenzyl)-4-methylphenol,2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane,tetra-4-[4-hydroxyphenylisopropyl]-phenoxy)-methane,1,4-bis-[4,4′-dihydroxytriphenyl)-methyl]-benzene, in amounts of 0.01 to1.0 mol. %, with respect to the diphenols used. Phenolic branchingagents may be initially introduced with the diphenols, acid chloridebranching agents may be introduced together with the acid dichlorides.

In the thermoplastic, aromatic polyestercarbonates, the proportion ofcarbonate structural units may be any value at all. The proportion ofcarbonate groups is preferably up to 100 mol. %, in particular up to 80mol. %, especially up to 50 mol. %, with respect to the sum of estergroups and carbonate groups. Both the ester fraction and the carbonatefraction of the aromatic polyestercarbonates may be present in the formof blocks or may be distributed statistically within the polycondensate.

The relative viscosity (η_(rel)) of the aromatic polycarbonates andpolyester carbonates is in the range 1.18 to 1.4, preferably 1.22 to 1.3(measured using solutions of 0.5 g of polycarbonate orpolyestercarbonate in 100 ml of methylene chloride solution at 25° C.).

The thermoplastic, aromatic polycarbonates and polyestercarbonates maybe used separately or as any mixture with each other.

Component B

Component B contains one or more graft polymers of

-   B.1 5 to 95, preferably 30 to 80 wt. %, of at least one vinyl    monomer on-   B.2 95 to 5, preferably 70 to 20 wt. % of one or more particulate    diene rubbers with glass transition temperatures <10° C., preferably    <0° C., in particular <−10° C.,    -   which are prepared by emulsion polymerisation using an initiator        system consisting of an organic hydroperoxide and ascorbic acid.    -   Graft substrate B.2 generally has an average particle size (d₅₀        value) of 0.05 to 5 μm, preferably 0.10 to 0.6 μm, in particular        0.20 to 0.40 μm.

Monomers B.1 are preferably mixtures of

-   B.1.1 50 to 99 parts by wt. of vinyl aromatic compounds and/or    ring-substituted vinyl aromatic compounds (such as, for example,    styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene) and/or    (C₁-C₈) alkyl methacrylates (such as e.g. methyl methacrylate, ethyl    methacrylate) and-   B.1.2 1 to 50 parts by wt. of vinyl cyanides (unsaturated nitrites    such as acrylonitrile and methacrylonitrile) and/or (C₁-C₈) alkyl    (meth)acrylates (such as e.g. methyl methacrylate, n-butyl acrylate,    t-butyl acrylate) and/or derivatives (such as anhydrides and imides)    of unsaturated carboxylic acids (for example maleic anhydride and    N-phenyl-maleic imide).

Preferred monomers B.1.1 are selected from at least one of the monomersstyrene, α-methylstyrene and methyl methacrylate, preferred monomersB.1.2 are selected from at least one of the monomers acrylonitrile,maleic anhydride and methyl methacrylate.

Particularly preferred monomers are B.1.1 styrene and B.1.2acrylonitrile.

Preferred graft substrates B.2 are diene rubbers (e.g. based onbutadiene, isoprene, etc.) or mixtures of diene rubbers or copolymers ofdiene rubbers or their mixtures with further copolymerisable monomers(e.g. in accordance with B.1.1 and B1.2) with the proviso that the glasstransition temperature of component B.2 is <10° C., preferably <0° C.,particularly preferably <−10° C. and in particular <−20° C.

Pure polybutadiene rubber is particularly preferred.

Graft polymers with the following constituents are particularlypreferred

-   a) 40 to 90 wt. % of particulate diene rubber with an average    particle diameter of 0.1 to 0.6 μm and-   b) 60 to 10 wt. % of styrene, acrylonitrile, methyl methacrylate or    mixtures of these, produced by emulsion graft polymerisation,    which are characterised in that an initiator system consisting of an    organic hydroperoxide and ascorbic acid is used for graft    polymerisation, with the production of a graft yield of >60 wt. %,    preferably >75 wt. %, in particular >85 wt. % (with respect to the    monomers B.1 or b used).

According to one embodiment, graft polymerisation of monomers a) isperformed in aqueous emulsion in the presence of an emulsion of rubberpolymer b) at temperatures of 40 to 70° C., in particular 50 to 70° C.,using an initiator system consisting of organic hydroperoxide (I) andascorbic acid (II), wherein 0.3 to 1.5 parts by wt. of (I) and 0.1 to 1part by wt. of (II), each with respect to 100 parts by wt. of graftpolymer, are generally used and the ratio by weight (I):(II) is 0.3 to15, in particular 1 to 10, preferably 3 to 8 (see DE-A-37 08 913 (=U.S.Pat. No. 4,859,744) and EP-A-315 868 (=U.S. Pat. No. 4,937,285)).

The rubbers are generally partly cross-linked and have gel contents of10 to 90 wt. %, in particular of 40 to 80 wt. % and are particulate withaverage particle sizes (d₅₀ , value) of 0.1 to 0.6 μm, in particular 0.2to 0.4 μm. These types of particulate rubbers are known. They areprepared by emulsion polymerisation and are generally available aslatices.

The graft polymers are prepared in aqueous emulsion by polymerising themonomers on a rubber present in aqueous emulsion. Surface-activeauxiliary agents are generally used; emulsifiers or dispersants and alsooptionally additives in order to adjust the pH and electrolyte contentsto specific values during graft polymerisation. In some circumstances,emulsion graft polymerisation may also be performed without the additionof an emulsifier, in particular when small amounts of monomers are used,with respect to the amount of rubber, or when the amounts of emulsifieralready present in the rubber emulsion (latex) itself are sufficient toensure graft polymerisation of the monomers in the emulsified state withadequate emulsion stability.

Anionic emulsifiers are particularly suitable, preferably alkali metalsalts of fatty acids, resin acids, disproportionated resin acids,alkylsulfonic acids, arylsulfoninc acids. They are used in amounts of upto 5 wt. %, preferably up to 2.5 wt. %, with respect to the monomersbeing polymerised.

Suitable hydroperoxides are, for example, cumyl hydoperoxide,tert.-butyl hydroperoxide, hydrogen peroxide, preferably cumylhydroperoxide and tert.-butyl hydroperoxide, that is hydroperoxides withlong half life periods.

An aqueous emulsion of a partially cross-linked diene rubber is graftedbatchwise or continuously in aqueous emulsion; at polymerisationtemperatures of 40 to 70° C., in particular 50 to 70° C., the graftmonomers and optionally additional emulsifier and hydroperoxide andascorbic acid solutions are added to the rubber emulsion. The ratios byweight mentioned above should be observed during this procedure. Inexceptional cases, catalytically small amounts of heavy metal cations,in particular Fe, may be added as a further component of the startersystem for polymerisation, especially when diene rubber emulsions haveto be used which themselves already contain large amounts of complexingagents. Normally, no iron ions are added in the process; this method ispreferred and enables the recovery of industrially advantageous graftpolymers which contain virtually no heavy metals, or only very smallamounts, since it is known that traces of such metals can have adeleterious effect on the application-oriented properties of plastics.The process is performed using aqueous solutions of ascorbic acid andaqueous solutions of hydroperoxide. It is advantageous to feedinsufficiently water-soluble hydroperoxides, such as cumylhydroperoxide, to the polymerisation system in the form of an aqueousemulsion. The same emulsifier is advantageously used in these emulsionsas is used for graft polymerisation.

The hydroperoxide and ascorbic acid may be added to the graftpolymerisation system in portions or continuously. In a preferredvariant, the hydroperoxide is initially introduced into the reactorproportionately with the rubber to be grafted; the graft monomers andthe remaining ascorbic acid, hydroperoxide and optionally emulsifier arefed separately into the reactor as polymerisation of the graft monomersproceeds.

The amounts of hydroperoxide and ascorbic acid are critical. If too muchhydroperoxide and/or ascorbic acid are added, the graft polymerisationprocess is impaired. The graft yield is reduced; the molecular weight ofthe grafted and free resin is lower. Undershooting or exceeding theamounts of hydroperoxide and ascorbic acid can also have a sensitiveeffect on monomer conversion and the stability of the emulsion, so thatindustrial achievement of the graft polymerisation process becomesimpossible. In order to perform the process and to optimise thestructure of the graft polymer and its physical properties, it isessential to maintain a temperature of 40 to 70° C. and to observe theamounts of hydroperoxide/ascorbic acid mentioned above.

In the case of graft polymerisation up to monomer conversions of greaterthan 90 wt. %, in particular greater than 98 wt. %, storage-stable graftpolymer emulsions with polymer concentrations of 25 to 50 wt. % areproduced. The graft polymer itself can readily be isolated from theemulsions by known methods of coagulation (e.g. using acids or salts).If the graft polymer is to be combined with thermoplastic resins, whichare themselves present as an emulsion, then the graft polymer emulsioncan be mixed with the resin emulsion and the mixture can be coagulatedas one.

The gel content of graft substrate B.2 is determined at 25° C. in asuitable solvent (M. Hoffman, H. Krömer, R. Kuhn, Polymeranalytik I andII, Georg Thieme-Verlag, Stuttgart, 1977).

The average particle size d₅₀ is the diameter, above and below which 50wt. % of the diameters of the particles are found. It can be determinedby means of ultracentrifuge measurements (W. Scholtan, H. Lange,Kolloid, Z. und Z. Polymere 250 (1972), 782-796).

Component C

Component C contains one or more thermoplastic vinyl (co)polymers C.1and/or polyalkylene terephthalates C.2.

(Co)polymers which are suitable for use as C.1 are polymers of at leastone monomer from the group of vinyl aromatic compounds, vinyl cyanides(unsaturated nitrites), (C₁-C₈) alkyl (meth)acrylates, unsaturatedcarboxylic acids and derivatives (such as anhydrides and imides) ofunsaturated carboxylic acids. Particularly suitable (co)polymers arethose made from

-   C.1.1 50 to 99, preferably 60 to 80 parts by wt. of vinyl aromatic    compounds and/or ring-substituted vinyl aromatic compounds (such as,    for example, styrene, α-methylstyrene, p-methylstyrene,    p-chlorostyrene) and/or (C₁-C₄) alkyl (meth)acrylates (such as e.g.    methyl methacrylate, ethyl methacrylate), and-   C.1.2 1 to 50, preferably 20 to 40 parts by wt. of vinyl cyanides    (unsaturated nitrites) such as acrylonitrile and methacrylonitrile    and/or (C₁-C₈) alkyl (meth)acrylates (such as e.g. methyl    methacrylate, n-butyl acrylate, t-butyl acrylate) and/or unsaturated    carboxylic acids (such as maleic acid) and/or derivatives (such as    anhydrides and imides) of unsaturated carboxylic acids (for example    maleic anhydride and N-phenyl-maleic imide).

(Co)polymers C.1 are resinous, thermoplastic and rubber-free.

The copolymer is particularly preferably composed of C.1.1 styrene andC.1.2 acrylonitrile.

(Co)polymers in accordance with C.1 are known and can be prepared byradical polymerisation, in particular by emulsion, suspension, solutionor bulk polymerisation. (Co)polymers in accordance with component C.1preferably have molecular weights M_(W) (weight average, determined bylight scattering or sedimentation) between 15 000 and 200 000.

The polyalkylene terephthalates in component C.2 are reaction productsof aromatic dicarboxylic acids or their reactive derivatives, such asdimethyl esters or anhydrides, and aliphatic, cycloaliphatic oraraliphatic diols and also mixtures of these reaction products.

Preferred polyalkylene terephthalates contain at least 80 wt. %,preferably at least 90 wt. %, with respect to the dicarboxylic acidcomponent, of terephthalic acid groups and at least 80 wt. %, preferablyat least 90 wt. %, with respect to the diol component, of ethyleneglycol and/or butanediol-1,4 groups.

Preferred polyalkylene terephthalates may contain, in addition toterephthalates, up to 20mol. %, preferably up to 10 mol. % of groupsfrom other aromatic or cycloaliphatic dicarboxylic acids with 8 to 14carbon atoms or aliphatic dicarboxylic acids with 4 to 12 carbon atoms,such as e.g. groups from phthalic acid, isophthalic acid,naphthalene-2,6dicarboxylic acid, 4,4′-diphenyldicarboxylic acid,succinic acid, adipic acid, sebacic acid, azelaic acid,cyclohexane-diacetic acid.

Preferred polyalkylene terephthalates may contain, in addition toethylene glycol or butanediol-1,4 groups, up to 20 mol. %, preferably upto 10 mol. %, of other aliphatic diols with 3 to 12 carbon atoms orcycloaliphatic diols with 6 to 21 carbon atoms, e.g. groups frompropanediol-1,3, 2-ethylpropanediol-1,3, neopentyl glycol,pentanediol-1,5, hexanediol-1,6, cyclohexane-dimethanol-1,4,3-ethylpentanediol-2,4, 2-methylpentanediol-2,4,2,2,4-trimethylpentanediol-1,3, 2-ethylhexanediol-1,3,2,2-diethylpropanediol-1,3, hexanediol-2,5,1,4-di-(β-hydroxyethoxy)-benzene, 2,2-bis-(4-hydroxycyclohexyl)-propane,2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane,2,2-bis-(4-β-hydroxyethoxyphenyl)-propane and2,2-bis-(4-hydroxypropoxyphenyl)-propane (DE-OS 2 407 674, 2 407 776, 2715 932).

The polyalkylene terephthalates may be branched by incorporatingrelatively small amounts of trihydric or tetrahydric alcohols ortribasic or tetrabasic carboxylic acids, e.g. in accordance with DE-OS 1900 270 and U.S. Pat. No. 3,692,744. Examples of preferred branchingagents are trimesic acid, trimellitic acid, trimethylolethane and-propane and pentaerythritol.

Particularly preferred polyalkylene terephthalates are those which havebeen prepared solely from terephthalic acid and its reactive derivatives(e.g. its dialkyl esters) and ethylene glycol and/or butanediol-1,4, andmixtures of these polyalkylene terephthalates.

Mixtures of polyalkylene terephthalates contain 1 to 50 wt. %,preferably 1 to 30 wt. %, of polyethylene terephthalate and 50 to 99 wt.%, preferably 70 to 99 wt. %, of polybutylene terephthalate.

Preferably used polyalkylene terephthalates generally have an intrinsicviscosity of 0.4 to 1.5 dl/g, preferably 0.5 to 1.2 dl/g, measured inphenol/o-dichlorobenzene (1:1 by weight) at 25° C. in an Ubbelohdeviscometer.

Polyalkylene terephthalates can be prepared by known methods (see e.g.Kunststoff-Handbuch, vol. VIII, p. 695 et seq., Carl-Hanser-Verlag,Munich 1973).

Component D

Moulding compositions according to the invention contain, as a flameretardant, at least one phosphonate amine compound of the formula (I)A_(3-y)-N—B_(y)  (I),in which

wherein

-   R¹, R², R³ and R⁴ and also B and y are defined in the same way as    given above.-   B preferably represents, independently, hydrogen, ethyl, n-propyl or    iso-propyl, which may be substituted by halogen, or a C₆-C₁₀ aryl    group which is unsubstituted or substituted by a C₁-C₄ alkyl group    and/or by halogen, in particular phenyl or naphthyl.

Alkyl in R¹, R², R³ and R⁴ preferably represents, independently, methyl,ethyl, n-propyl, iso-propyl, n-, iso-, sec. or tert.-butyl, pentyl orhexyl.

Substituted alkyl in R¹, R², R³ and R⁴ preferably represents,independently, a C₁-C₁₀ alkyl group substituted by halogen, inparticular for mono- or di-substituted methyl, ethyl, n-propyl,iso-propyl, n-, iso-, sec. or tert.-butyl, pentyl or hexyl.

R³ and R⁴, together with the carbon atom to which they are bonded,preferably form cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl, inparticular cyclopentyl or cyclohexyl.

C₆-C₁₀ aryl in R¹ , R², R³ and R⁴, independently, preferably representsphenyl, naphthyl or binaphthyl, in particular o-phenyl, o-naphthyl,o-binaphthyl, which may be substituted by halogen (in general once,twice or three times).

The following are mentioned by way of example and for preference:5,5,5′,5′,5″,5″-hexamethyl-tris-(1,3,2-dioxaphosphorinane-methane)-amino-2,2′,2″-trioxideof the formula (I-1)

(trial product XPM 1000, from Solutia Inc., St. Louis, USA)

1,3,2-dioxaphosphorinane-2-methanamine,N-butyl-N[(5,5dimethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-5,5-dimethyl-,P,2dioxide; 1,3,2-dioxaphosphorinane-2-methanamine,N-[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-5,5-dimethyl-N-phenyl-,P,2-dioxide; 1,3,2-dioxaphosphorinane-2-methanamine,N,N-dibutyl-5,5-dimethyl-, 2-oxide,1,3,2-dioxaphosphorinane-2-methanamine,N-[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-N-ethyl-5,5-dimethyl-,P,2-dioxide, 1,3,2-dioxaphosphorinane-2-methanamine,N-butyl-N-[(5,5-dichloromethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-5,5-dichloromethyl-,P,2-dioxide, 1,3,2-dioxa-phosphorinane-2-methanamine,N-[(5,5-di-chloromethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-5,5-di-chloromethyl-N-phenyl-,P,2-dioxide; 1,3,2-dioxaphosphorinane-2-methanamine,N,N-di-(4-chlorobutyl)-5,5-dimethyl-2-oxide;1,3,2-dioxaphosphorinane-2-methanamine,N-[(5,5dimethyl-1,3,2-dioxaphosphorinan-2-yl)-methane]-N-(2-chloroethyl)-5,5di-(chloromethyl)-,P2-dioxide.

Also preferred are:compounds of the formula (I-2) or (I-3)

whereinR¹, R², R³ and R⁴ are defined in the same way as above.

Compounds of the formula (I-2) and (I-1) are particularly preferred. Theindividual compounds mentioned above are also particularly preferred.

Compounds of the formula (I) can be prepared by the following process:

-   a) PCl₃ is added to a mixture of 1,3-diol derivatives, water and an    organic solvent at a temperature of 10-60° C. A 5,5-disubstituted    1,3,2-dioxaphosphorinane-2-oxide of the formula (Ia) is obtained    -   wherein R¹ and R² are defined in the same way as above,-   b) after purification, the 1,3,2-dioxaphosphorinane-2-oxide is    reacted, in paraformaldehyde, with an amine B_(y)NH_(3-y), wherein B    and y are defined in the same way as above,-   c) after purifying again and drying, the phosphonate amine of the    formula (I) is obtained.

A detailed description of the method of preparation can be found in U.S.Pat. No. 5,844,028.

Component E

Fluorinated polyolefins E have high molecular weights and have glasstransition temperatures higher than −30° C., generally higher than 100°C., and fluorine contents of preferably 65 to 76, in particular 70 to 76wt. %, average particle diameters d₅₀ of 0.05 to 1 000, preferably 0.08to 20 μm. Fluorinated polyolefins E generally have a density of 1.2 to2.3 g/cm³. Preferred fluorinated polyolefins E arepolytetrafluoroethylene, polyvinylidene fluoride,tetrafluoroethylene/hexafluoropropylene and ethylene/tetrafluoroethylenecopolymers. The fluorinated polyolefins are known (see “Vinyl andRelated Polymers” by Schildknecht, John Wiley & Sons, Inc., New York,1962, pages 484-494; “Fluorpolymers” by Wall, Wiley-Interscience, JohnWiley & Sons, Inc., New York, vol. 13, 1970, pages 623-654; “ModernPlastics Encyclopedia”, 1970-1971, vol. 47, no. 10 A, October 1970,McGraw-Hill, Inc., New York, pages 134 and 774; “Modern PlasticsEncyclopedia”, 1975-1976, October 1975, vol. 52, no. 10 A, McGraw-Hill,Inc., New York, pages 27, 28 and 472 and U.S. Pat. Nos. 3,671,487,3,723,373 and 3,838,092).

They can be prepared by known processes, that is, for example, bypolymerising tetrafluoroethylene in aqueous medium with a freeradical-producing catalyst, for example sodium, potassium or ammoniumperoxydisulfate, at pressures of 7 to 71 kg/cm² and at temperatures of 0to 200° C., preferably at temperatures of 20 to 100° C. (For moredetails, see e.g. U.S. Pat. No. 2,393,967). Depending on the initialform, the density of these materials is between 1.2 and 2.3 g/cm³ andthe average particle size is between 0.5 and 1 000 μm.

According to the invention, preferred fluorinated polyolefins E aretetrafluoroethylene polymers with average particle diameters of 0.05 to20 μm, preferably 0.08 to 10 μm, and a density of 1.2 to 1.9 g/cm³ andare preferably used in the form of a coagulated mixture of emulsions oftetrafluoroethylene polymer E and emulsions of the graft polymers B.

Further preparations which are preferred according to the invention arefluorinated polyolefins E:

-   E.1) as a coagulated mixture with at least one of components A to C,    wherein the fluorinated polymer B or polyolefin mixture as an    emulsion is mixed with at least one emulsion of the components A to    C and is then coagulated or-   E.2) as a pre-compound with at least one of components A to C,    wherein the fluorinated polyolefin E as a powder is mixed with a    powder or granules of at least one of the components A to C and is    compounded in the molten state, in general at temperatures of    208° C. to 330° C. in conventional equipment such as internal    compounders, extruders or twin-shaft screws.

Preferred preparations of fluorinated polyolefin E are coagulatedmixtures with a graft polymer B or a vinyl (co)polymer C.

Fluorinated polyolefins E which are suitable for use in powdered formare tetrafluoroethylene polymers with average diameters of 100 to 1 000μm and densities of 2.0 g/cm³ to 2.3 g/cm³.

To prepare a coagulated mixture of B and E, an aqueous emulsion (latex)of a graft polymer B is first mixed with a finely divided emulsion of atetrafluoroethylene polymer E; suitable tetrafluoroethylene polymeremulsions normally have solids contents of 30 to 70 wt. %, preferably 50to 60 wt. %, in particular 30 to 35 wt. %.

The ratio by weight of graft polymer B or (co)polymer to fluorinatedpolyolefin E in the emulsion mixture is 95:5 to 60:40, preferably 90:10to 50:50. Then, the emulsion mixture is coagulated in a known manner,for example by spray-drying, freeze-drying or coagulation by means ofadding inorganic or organic salts, acids, bases or water-miscibleorganic solvents such as alcohols or ketones, preferably at temperaturesof 20 to 150° C., in particular 50 to 100° C. If required, the mixturemay be dried at 50 to 200° C., preferably 70 to 100° C.

Suitable tetrafluoroethylene polymer emulsions are commerciallyavailable products and are sold, for example, by DuPont as Teflon® 30 N.

Moulding compositions according to the invention may contain at leastone of the conventional additives such as lubricants and mould-releaseagents, nucleating agents, antistatic agents, stabilisers or colorantsand pigments.

Moulding compositions according to the invention may contain up to 35wt. %, with respect to the entire moulding composition, of a further,optionally synergistic, flame retardant. Examples of further flameretardants which may be mentioned are organic halogenated compounds suchas decabromobisphenyl ether, tetrabromobisphenol, inorganic halogencompounds such as ammonium bromide, nitrogen compounds such as melamine,melaminelformaldehyde resins, inorganic hydroxide compounds such as Mgor Al hydroxide, inorganic compounds such as antimony oxides, bariummetaborate, hydroxoantimonate, zirconium oxide, zirconium hydroxide,molybdenum oxide, ammonium molybdate, zinc borate, ammonium borate,talc, silicones, silicon dioxide and tin oxide and also siloxanecompounds.

Furthermore, phosphorus compounds of the formula (VI) are suitable asflame retardants,

in which

-   R⁷, R⁸ and R⁹, independently, represent an optionally halogenated    C₁-C₈ alkyl or and optionally halogenated and/or alkylated C₅ or C₆    cycloalky or an optionally halogenated and/or alkylated and/or    aralkylated C₆-C₃₀ aryl group and-   “n” and “1”, independently, are 0 or 1.

These phosphorus compounds are generally known (see for example,Ullmann, Enzyklopädie der technischen Chemie, vol. 18, pages 301 etseq., 1979 and EP-A 345 522). Aralkylated phosphorus compounds aredescribed, for example, in DE-OS 38 24 356.

Optionally halogenated C₁-C₈ alkyl groups in accordance with (VI) maycontain one or more halogen atoms and be linear or branched. Examples ofalkyl groups are chloroethyl, 2-chloropropyl, 2,3-dibromopropyl, butyl,methyl or octyl.

Optionally halogenated and/or alkylated C₅ or C₆ cycloalkyl groups inaccordance with (VI) are optionally singly or multiply halogenatedand/or alkylated C₅ or C₆ cycloalkyl groups, that is e.g. cyclopentyl,cyclohexyl, 3,3,5-trimethylcyclohexyl and fully chlorinated cyclohexyl.

Optionally halogenated and/or alkylated and/or aralkylated C₆-C₃₀ arylgroups in accordance with (VI) are optionally mononuclear orpolynuclear, singly or multiply halogenated and/or alkylated and/oraralkylated groups, e.g. chlorophenyl, bromophenyl, pentachlorophenyl,pentabromophenyl, phenyl, cresyl, isopropylphenyl, benzyl-substitutedphenyl and naphthyl.

R⁷, R₈ and R⁹ preferably represent, independently, methyl, ethyl, butyl,octyl, phenyl, cresyl, cumyl or naphthyl. R⁷, R⁸ and R⁹, independently,represent in particular methyl, ethyl or butyl or phenyl which isoptionally substituted by methyl and/or ethyl.

Phosphorus compounds in accordance with formula (VI) which may be usedaccording to the invention arc e.g. tributyl phosphate,tris-2-chloroethyl) phosphate, tris-(2,3-dibromopropyl) phosphate,triphenyl phosphate, tricresyl phosphate, diphenylcresyl phosphate,diphenyloctyl phosphate, diphenyl-2-ethylcresyl phosphate,tri-(isopropylphenyl) phosphate, tris-(p-benzylphenyl) phosphate,triphenylphosphine oxide, dimethyl methanephosphonate, diphenylmethanephosphonate and diethyl phenylphosphonate.

Suitable flame retardants are also dimeric and oligomeric phosphatessuch as are described, for example, in EP-A-0 363 608.

Moulding compositions according to the invention may also containphosphorus compounds in accordance with formula (VII) as flameretardants

In the formula, R¹⁰, R¹¹, R¹² and R₁₃, independently, each representoptionally halogenated C₁-C₈ alky, C₅-C₆ cycloalkyl, C₆-C₂₀ aryl orC₇-C₁₂ aralkyl groups.

R¹⁰, R¹¹, R¹² and R¹³, independently, preferably represent C₁-C₄ alkyl,phenyl, naphthyl or phenyl-C₁-C₄-alkyl groups. Aromatic groups R¹⁰, R¹¹,R¹² and R¹³ may for their part be substituted with halogen atoms and/oralkyl groups, preferably chlorine, bromine and/or C₁-C₄ alkyl groups.Particularly preferred aryl groups are cresyl, phenyl, xylenyl,propylphenyl or butylphenyl and also the corresponding brominated andchlorinated derivatives thereof.

-   X in formula (VII) represents a mononuclear or polynuclear aromatic    group with 6 to 30 carbon atoms. This is preferably derived from    diphenols of the formula (II). Diphenylphenol, bisphenol A,    resorcinol or hydroquinone or their chlorinated or brominated    derivatives are particularly preferred.-   n in formula (VII) may, independently, be 0 or 1; n is preferably    equal to 1.-   k has a value from 0 to 30 and preferably has an average value from    0.3 to 20, in particular 0.5 to 10, specifically 0.5 to 6.

Mixtures of 10 to 90 wt. %, preferably 12 to 40 wt. %, of at least onemonophosphorus compound of the formula (VI) and at least one oligomeric.phosphorus compound, for example a mixture of oligomeric phosphoruscompounds such as those described in EP-A-363 608 and phosphoruscompounds in accordance with formula (VII) in amounts of 10 to 90 wt. %,preferably 60 to 88 wt. %, with respect to the total amount ofphosphorus compounds, may also be used.

Monophosphorus compounds of the formula (VI) are in particular tributylphosphate, tris-(2-chloroethyl) phosphate, tris-2,3-dibromopropyl)phosphate, triphenyl phosphate, tricresyl phosphate, diphenylcresylphosphate, diphenyloctyl phosphate, diphenyl-2-ethylcresyl phosphate,tri-(isopropylphenyl) phosphate, halogen-substituted aryl phosphates,dimethyl methylphosphonate, diphenyl methylphosphonate and diethylphenylphosphonate, triphenylphosphine oxide or tricresylphosphine oxide.

The mixtures of monomeric and oligomeric phosphorus compounds of theformula (VII) have average k values of 0.3 to 20, preferably 0.5 to 10,in particular 0.5 to 6.

The phosphorus compounds mentioned are known (e.g. EP-A-363 608,EP-A-640 655) or can be prepared in a similar manner by known methods(e.g. Ullmanns Encyclopädie der technischen Chemie, vol. 18, p. 301 etseq., 1979; Houben-Weyl, Methoden der organischen Chemie, vol. 12/1, p.43; Beilstein vol. 6, p. 177).

Moulding compositions according to the invention containing components Ato E and optionally further known additives such as stabilisers,colorants, pigments, lubricants and mould release agents, nucleatingagents and antistatic agents, are prepared by mixing the relevantconstituents in a known manner and melt compounding and melt extrudingat temperatures of 200° C. to 300° C. in conventional equipment such asinternal compounders, extruders and twin-shaft screws, wherein componentE is preferably used in the form of the coagulated mixture mentionedabove.

Mixing the individual constituents may take place in a known mannereither in sequence or simultaneously, in fact either at about 20° C.(room temperature) or at a higher temperature.

Due to their exceptional flame resistance and good mechanicalproperties, thermoplastic blends according to the invention are suitablefor producing moulded articles of any type, in particular those withhigh demands relating to resistance to breaking.

Moulding compositions according to the present invention may be used toproduce moulded articles of any type. In particular, moulded articlesmay be produced by injection moulding. Examples of moulded articleswhich can be produced are: housing sections of any type, e.g. fordomestic equipment such as juice presses, coffee machines, mixers, foroffice machines such as monitors, printers, copiers or cladding for theconstruction sector and parts for the car sector. They can also be usedin the electrical engineering area because they have very goodelectrical properties.

Furthermore, moulding compositions according to the invention may beused, for example, to produce the following moulded articles or mouldedparts:

Internal structural parts for rail vehicles (FR), hub caps, housings forsmall transformers containing electrical equipment, housings forequipment for information distribution and transmission, housings andcovers for medical purposes, massage equipment and housings therefor,toy vehicles for children, flat wall panels, housings for safetydevices, rear spoilers, thermally insulated ansport containers, devicesfor housing or caring for small animals, moulded parts for sanitary andbath fittings, cover grids for ventilation openings, moulded parts forsummerhouses and garden sheds, housings for garden equipment.

Another form of processing is the production of moulded articles bythermoforming from previously produced sheets or films.

Therefore, the present invention also provides use of mouldingcompositions according to the invention to produce moulded articles ofany type, preferably the articles mentioned above, and the mouldedarticles made from moulding compositions according to the invention.

EXAMPLE

Component A

Linear polycarbonate based on bisphenol A with a relative solutionviscosity of 1.252 measured in CH₂Cl₂ as solvent at 25° C. and at aconcentration of 0.5 g/100 ml.

Component B

Graft Substrate:

-   B.2 An emulsion of a partially cross-linked polybutadiene with a    mean particle diameter of 0.28 μm (d₅₀ value) and a gel content of    55 wt. %. The emulsion contains 50 wL% of polymeric solids.    Preparing the Graft Polymer:-   Ba) A graft polymer consisting of 60 wt. % of a diene rubber (B.2)    and 40 wt. % of a SAN copolymer in accordance with DE-A 37 08 913.    -   A mixture of 200 parts by wt. of latex (B.2) and 149 parts by        wt. of water are initially introduced into a reactor and heated        to 60 to 62° C. At this temperature, the following two solutions        or emulsions are introduced into the reactor in the following        sequence:    -   1. 0.0836 parts by wt. of cumyl hydroperoxide        -   6.9600 parts by wt. of water        -   0.0600 parts by wt. of the Na salt of C₁₄-C₁₆ alkylsulfonic            acids    -   2. 0.0557 parts by wt. of ascorbic acid        -   6.9600 parts by wt. of water    -   Then, the following feed streams are supplied to the reactor,        with stirring, over the course of 4 hours and with an internal        temperature of 60 to 62° C.:    -   Z1) 39.05 parts by wt. of water        -   4.00 parts by wt. of the Na salt of disproportionated            abietic acid        -   3.10 parts by wt. of 1N caustic soda solution        -   0.62 parts by wt. of cumyl hydroperoxide    -   Z2) 59 parts by wt. of styrene        -   23 parts by wt. of acrylonitrile    -   Z3) 39.800 parts by wt. of water        -   00.105 parts by wt. of ascorbic acid    -   The mixture is then polymerised at 60 to 62° C. for a further 6        hours. The monomer conversion is greater than 97 wt. %.    -   After stabilising with 1.2 parts by wt. of phenolic antioxidant,        per 100 parts by wt. of graft polymer, the graft polymer is        isolated by coagulating with an acetic acid/Mg sulfate mixture,        washed and dried to form a powder.    -   SAN grafting proceeded with a graft yield of 89 wt. %.    -   The graft yield was determined by fractionating de-mixing with        the de-mixing liquids dimethylformamide/methylcyclohexane in an        ultracentrifuge and by determining the amounts and chemical        composition of the fractions obtained in this way (see R. Kuhn,        Makromol-Chemie 177, 1525 (1976)).        Component C

Styrene/acrylonitrile copolymer with a styrenelacrylonitrile ratio byweight of 72:28 and an intrinsic viscosity of 0.55 dl/g (measured indimethylformamide at 20° C.).Component D

(XPM 1000 development product from Solutia Inc., St. Louis, USA).Component E

Tetrafluoroethylene polymer as a coagulated mixture of an SAN graftpolymer emulsion in accordance with component B described above in waterand a tetrafluoroethylene polymer emulsion in water. The ratio by weightof graft polymer B to tetrafluoroethylene polymer E in the mixture is 90wt. % to 10 wt. %. The tetrafluoroethylene polymer emulsion has a solidscontent of 60 wt. %, the mean particle diameter is between 0.05 and 0.5μm. The SAN graft polymer emulsion has a solids content of 34 wt. % andan average latex particle diameter of d₅₀=0.28 μm.

Preparing E

The emulsion of tetrafluoroethylene polymer (Teflon 30 N from DuPont) ismixed with the emulsion of SAN graft polymer B and stabilised with 1.8wt. %, with respect to polymeric solids, of phenolic antioxidant. Themixture is coagulated at 85 to 95° C. using an aqueous mixture of MgSO₄(Epsom salts) and acetic acid at a pH of 4 to 5, filtered and washeduntil virtually free of electrolytes. Then, the major proportion ofwater is removed by centrifuging and the residue to dried at 100° C. toproduce a powder. This powder can then be compounded with the othercomponents in the equipment described.

Preparing and Testing Moulding Compositions According to the Invention

The components were mixed in a 3 l internal compounder. The mouldedarticles were prepared at 260° C. on an injection moulding machine ofthe Arburg 270 E type.

The heat resistance according to Vicat B was determined in accordancewith DIN 53 460 (ISO 306) using rods with the dimensions 80×10×4 mm.

The weld line strength (a_(n)) was determined by measuring the impactresistance according to DIN 53 453 at the weld line on both sides of aninjection moulded specimen (processing temperature 260° C.) with thedimensions 170×10×4 mm.

The stress crack behaviour (ESC behaviour) was investigated using rodswith the dimensions 80×10×4 mm, processing temperature 260° C. A mixtureof 60 vol. % toluene and 40 vol. % isopropanol was used as the testmedium. The specimens were pre-stretched using an arc-shaped jig(pre-stretching as a percentage) and stored at room temperature in thetest medium. The stress crack behaviour is assessed by the production ofcracks or a fracture, as a function of the pre-stretching in the testmedium.

The fire behaviour of the samples was measured in accordance withUL-Subj. 94 V on rods with the dimensions 127×12.7×1.6 mm, produced onan injection moulding machine at 260° C.

The UL 94 V test is performed as follows:

Samples of the substance are moulded to give rods with the dimensions127×12.7×1.6 mm. The rods are mounted vertically so that the lower faceof the specimen is located 305 mm above a strip of dressing material.Each test rod is ignited individually by means of two sequentialignition processes which last for 10 s, the burning characteristics areobserved after each ignition process and then the samples are assessed.To ignite the samples, a Bunsen burner with a 100 mm (3.8 inch) highblue flame of natural gas with a thermal content of 3.73×10⁴ kJ/m³ (1000BTU per cubic foot) is used.

UL 94 V-O classification covers the properties of the material describedbelow, which are tested in accordance with the UL 94 V instructions. Themoulding compositions in this class do not contain any samples whichburn for longer than 10 s after each application of the test flame; theyexhibit total flame times of not more than 50 s during the twoapplications of a flame to each set of samples; they do not contain anysamples which bun completely up to the retaining clip fastened to theupper end of the sample; they do not include any samples which ignitethe wadding arranged below the sample as a result of burning droplets orparticles; also, they do not contain any samples which glow for longerthan 30 s after removing the test flame.

Other UL 94 classifications are allocated to samples which are lessflame resistant or less self-extinguishing, because they give offflaming droplets or particles. These classifications are called UL 94V-1 and V-2. NJ3. means “non resistant” and relates to theclassification of samples which have a post-burning time of ≧30 s.

The composition and properties are summarised in the table given below.

TABLE Moulding compositions and their properties Example 1 Components(parts by wt.) A 68.4 Ba 6.8 C 9.3 D 10.8 E 4.2 Properties a_(k) (ISO180/1A) [kJ/m²] 43.5 Vicat B 120 [° C.] 116 UL 94 V 3.2 mm V-O a_(n)weld strength [kJ/m²] 4.9 ESC bebaviour 2.0 Fracture at ε_(x) [%]

When using the special graft polymer, prepared by means of a redoxinitiator system, in polycarbonate moulding compositions, goodmechanical properties are exhibited in the presence of phosphonate amineas a flame retardant. Good values for notched impact resistance (a_(k)),weld line strength and adequate stress crack resistance arcprerequisites for use in thin-walled housing parts.

1. Blends containing A) 40 to 99 parts by wt. of aromatic polycarbonateand/or polyestercarbonate, B) 0.5 to 60 parts by wt. of a graft polymer,characterised in that the graft polymers B consist of B.1) 5 to 95 wt. %of one or more vinyl monomers and B.2) 95 to 5 wt. % of one or moreparticulate diene rubbers with a glass transition temperature of <10°C., which are prepared by emulsion polymensation, wherein an initiatorsystem consisting of an organic hydroperoxide and ascorbic acid is usedfor graft polymerisation, C) 0 to 45 parts by wt. of at least onethermoplastic polymer, selected from the group consisting ofthermoplastic vinyl (co)polymers and polyalkylene terephthalates and D)0.1 to 30 parts by wt. of a phosphonate amine of the general formula (I)A_(3-y)-N—B_(y)  (I), in which A represents a group of the formula (IIa)

or (IIb)

R¹ and R², independently, represent an unsubstituted or substitutedC₁-C₁₀ alkyl group or an unsubstituted or substituted C₆-C₁₀ aryl group,R¹ and R⁴, independently, represent an unsubstituted or substitutedC₁-C₁₀ alkyl group or an unsubstituted or substituted C₆-C₁₀ aryl groupor R³ and R⁴ together represent an unsubstituted or substituted C₃-C₁₀alkylene group, y has the numerical value 0, 1 or 2 and B independently,represents hydrogen, an optionally halogenated C₂-C₈ alkyl group, anunsubstituted or substituted C₆-C₁₀ aryl group, E) 0 to 5 parts by wt.of a fluorinated polyolefin wherein the sum of the parts by wt. of allthe blend components is
 100. 2. Blends in accordance with claim 1,containing 60 to 98.5 parts by wt. of A, 1 to 40 parts by wt. of B, 0 to30 parts by wt. of C, 2 to 25 parts by wt. of D, and 0.1 to 3 parts bywt. of E.
 3. Blends according to claim 1 containing 2 to 25 parts by wt.of C.
 4. Blends according to claim 1 containing 5 to 20 parts by wt. ofD.
 5. Blends according to claim 1 wherein vinyl monomers B.1 aremixtures of B.1.1 50 to 99 parts by wt. of vinyl aromatic compoundsand/or ring-substituted vinyl aromatic compounds and/or C₁-C₈ alkyl(meth)acrylates and B.1.2 1 to 50 parts by wt. of vinyl cyanides and/orC₁-C₈ alkyl (meth)acrylates and/or derivatives of unsaturated carboxylicacids.
 6. Blends according to claim 1 wherein diene rubber is selectedfrom the group consisting of diene rubbers, mixtures of diene rubbers,copolymers of diene rubbers and mixtures of diene rubber with furthercopolymerisable monomers.
 7. Blends according claim 1 wherein the dienerubber is a polybutadiene rubber.
 8. Blends according to claim 1 whereinthe graft yield during polymerisation is >60 wt. %.
 9. Blends accordingto claim 1 wherein the graft yield is >75 wt. %.
 10. Blends according toclaim 1 wherein the graft yield is >85 wt. %.
 11. Blends according toclaim 1 wherein cumyl hydroperoxide, tert.-butyl hydroperoxide and/orhydrogen peroxide are used as hydroperoxides.
 12. Blends according toclaim 1 wherein D is selected from the group consisting of5,5,5′,5′,5″,5″-hexamethyl-tris-(1,3,2-dioxaphosphorinane-methane)-amino-2,2′,2″-trioxide,1,3,2-dioxaphosphorinane-2-methanamine,N-butyl-N[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-5,5-dimethyl-,P,2-dioxide; 1,3,2-dioxaphosphorinane-2-methanamine,N-[(5,5-dimethyl-1,3,2-dioxaphos-phorinan-2-yl)-methyl]-5,5dimethyl-N-phenyl-P,2-dioxide;1,3,2-dioxaphosphorinane-2-methanamine, N,N-dibutyl-5,5-dimethyl-,2-oxide, 1,3,2-dioxaphosphorinane-2-methanamine,N-[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-N-ethyl-5,5-dimethyl-,P,2-dioxide, 1,3,2-dioxaphosphorinane-2-methanamine,N-butyl-N-[(5,5-dichloromethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-5,5-di-chloromethyl-,P,2-dioxide, 1,3,2-dioxa-phosphorinane-2-methanamine,N-[(5,5-di-chloromethyl-1,3,2-dioxa-phosphorinan-2-yl)-methyl]-5,5-di-chloromethyl-N-phenyl-,P,2-dioxide; 1,3,2-dioxaphosphorinane-2-methanamine,N,N-di-(4-chlorobutyl)-5,5-di-methyl-2-oxide;1,3,2-dioxaphosphorinane-2-methanamine, andN-[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)-methane]-N-(2-chloroethyl)-5,5-di-(chloromethyl)-,P2-dioxide.
 13. Blends according to claim 1 containing at least oneadditive selected from the group consisting of lubricants and mouldrelease agents, nucleating agents, antistatic agents, stabilisers,colorants and pigments.
 14. Blends according to claim 1 containingfurther flame retardants which are different from component D.
 15. Aprocess for preparing moulding compositions in according with claim 1,wherein the components A to B and optionally further additives are mixedand melt compounded.
 16. A thermoplastic molding composition comprisingA) 40 to 99 parts by wt. of a member selected from the group consistingof aromatic polycarbonate and polyestercarbonate, B) 0.5 to 60 parts bywt. of a graft polymer that contains B.1) 5 to 95% relative to theweight of the graft polymer of one or more vinyl monomers and B.2) 95 to5% relative to the weight of the graft polymer of one or moreparticulate diene rubber substrate having a glass transition temperatureof <10° C., the diene rubber being the product of emulsionpolymerization wherein initiator system included an organichydroperoxide and ascorbic acid, C) 0 to 45 parts by wt. of at least onethermoplastic polymer, selected from the group consisting ofthermoplastic vinyl (co)polymers and polyalkylene terephthalates and D)0.1 to 30 parts by wt. of a phosphonate amine of the formula (I)A_(3-y)-N—B_(y)  (I), in which A represents a group of the formula (IIa)

or (IIb)

R¹ and R², independently, represent an unsubstituted or substitutedC₁-C₁₀ alkyl group or an unsubstituted or substituted C₈-C₁₀ aryl group,R³ and R⁴, independently, represent an unsubstituted or substitutedC₁-C₁₀ alkyl group or an unsubstituted or substituted C₆-C₁₀ aryl groupor R³ and R⁴ together represent an unsubstituted or substituted C₃-C₁₀alkylene group, y is 0, 1 or 2 and B independently, represents hydrogen,an optionally halogenated C₂-C₈ alkyl group, an unsubstituted orsubstituted C₆-C₁₀ aryl group, and E) 0 to 5 parts by wt. of afluorinated polyolefin the sum of the parts by wt. of A), B), C), D),and E) is
 100. 17. The composition of claim 16 wherein A is present inan amount of 60 to 98.5 parts by wt., B is present in an amount of 1 to40 parts by wt., C is present in an amount of 0 to 30 parts by wt., D ispresent in an amount of 2 to 25 parts by wt., and E is present in anamount of 0.1 to 3 parts by wt.
 18. The composition of claim 16 whereinB.1 is a mixture of B.1.1 50 to 99 parts by wt. of at least one memberselected from the group consisting of vinyl aromatic compound,ring-substituted vinyl aromatic compound and C₁-C₈ alkyl methacrylateand B.1.2 1 to 50 parts by wt. of at least one member selected from thegroup consisting of vinyl cyanide, C₁-C₈ alkyl (meth)acrylate andderivative of unsaturated carboxylic acid, wherein the total of B.1.1and B.1.2 being 100 parts by weight.
 19. The composition of claim 16wherein the substrate is polybutadiene rubber.
 20. The composition ofclaim 16 wherein hydroperoxide is a member selected from the groupconsisting of cumyl hydroperoxide, tert.-butyl hydroperoxide andhydrogen peroxide.
 21. A molded article comprising the composition ofclaim 16.